Daniel Hartung

Strength of Textile Composites — A Voxel Based Continuum Damage Mechanics Approach

Industrialised infusion processes enable a cost-effective possibility to produce textile composite structures compared to pre-impregnated composite systems (Prepregs). Particularly with regards to high performance structures one has to be familiar with the material behaviour and the failure characteristic to apply fibre reinforced composites profitable. In this publication a brief overview of the current research activities to characterise the mechanical behaviour, failure and strength of textile composites compared with prepreg systems is presented.

Experimental Determination of Interlaminar Material Properties of Carbon Fiber Composites

Non Crimp Fabric (NCF) provides a low-cost potential and competitive advantages for thick composite structures. In this chapter, a method will be presented to determine the interlaminar failure under combined through-thickness load conditions. Additionally, the in-plane failure behaviour of NCF composite is discussed and analysed. A new test setup, based on the idea of Arcan, determines the material properties. Test results of combined through-thickness loading are presented by in the form of a shear-compression failure curve. The tests are reproducible and reliable. The failure envelope is finally used to verify known failure criteria.

The preparation of a composite structure for a first large scale ground test of a smart and gapless wing leading edge

At the Institute of Composite Structures and Adaptive Systems (FA, Prof. Wiedemann) of the DLR the structure of a flexible and gapless wing leading edge has been developed for testing in large scale structure-system ground tests. The absence of gaps in a flexible wing leading edge allows for a significant noise reduction and provides an additional key technology for realizing wings with a fully natural laminar flow. In the years 2009 and 2010 the work in the project SmartLED within the 4th German Aviation Research Program (LuFo) was focused on the preparation and realization of the first ground test of the in the project developed overall system. The overall smart droop nose concept arose from the cooperation of Airbus and EADS, whereas the DLR Institute FA dealt with the structural design, the test of the material systems, the simulation of the overall system, and the development of manufacturing technologies for the composite structures to be employed in the planned tests. The detailed presentation of this work forms the content of this paper which has been made possible through the application of the process chain for composite structures established at the Institute FA of the DLR.